Railroad crossing guard



March 8, 1932. c M, AWS N 1,848,516

RAILROAD CROSSING GUARD Filed April 2, 1929 2 Sheets-Sheet l Mamh 1932- c. M. DAVISON RAILROAD CROSSING GUARD Filed April 2, 1929 2 Sheets-Sheet 2 Patented Mar. 8, 1932 I ame TATES PATENT OFFICE CLARENCE-M. DAVI SONQOF BALTIMORE, MARYLAND, ASSIGNOR, BY MESNE ASSIGN M'ENT S, T0 RAILWAY- H IGHWAY DEVICES CORPORATION, OF CHESTER, PENNSYL 'VANIA, ACORIPOR-ATION OF 13ELAW'ARE RAILROAD CROSSING GUARD Application filed April 2, 1929. Serial No. 351,903.

This. invention relates to improvements in railroad crossing guards for use at railroad grade crossings. r

The object of'the' invention isto provide novel andefiicient means for effecting decelerationof a vehicle and bringing the same to a full stop within a predetermined distance less than the distance between the guard and the railroad tracks;

More particularly, the invention contemplates a guard comprisinga pivoted support and a barrier, the latter being flexible and capable of. withstanding stresses that would bepla'cedfu'pon it by an approaching vehicle and transmitting. such stresses to other means for restrainingmovement of the vehicle and ultimately bringing it to a full stop.

- Preferably, thesupporting member for the flexible barrier. is of rigid; construction and pivotedat oneside of the road to swing in a .ioriz'ontalplane, means also being provided for. yieldingly' restraining swinging movement of the-support by an approachingvehicle. Thebarrier is preferably in the form of a cable adapted to, span theroad at that sid'eof the support from which vehicles approachthe tracks to be guarded. The support and cable are spaced apart from one another a distance sufficient to permit the cable to bedefiected but: not to an extent that the vehiclewill imp act against or damage the support. This spacing of the barrier and support may be accomplished by form ng the 5 support withan offset intermediate portion and" attaching the cable forming. the barrier to said support at points so it willspan said ofi'setportion. The cable barrier is carried on the support, so that the cable can be raised when the'guard is elevated from across the roadway, as during the absence of trains at or in the vicinity of the crossing.

"Another, object consists in arrangingthe flexible barrier on its support in such fashion aisto increase the resisting power which it is capable of withstanding. As stated, this flexible. barrier is preferably a wire cable and by permitting. it to be flexed without stretching, upon initial impact of an approaching vehi clefthe strains of loads which it can carry without breaking are greatly increased. This result is preferably obtained by attaching the cable at one end to the supportvby some yielding means and permitting such yieldingly attached end to travel a distance which will permit the cable to flex a predetermined distance before said yielding end is brought to a stop, after which further flexing of the cable is prevented and the strains transmitted to a snubbing device with which the cable vehicle impacting against the cable. In fact, 7

such yielding means need be of only sufficient strength as to take up slack in the cable'un'der normal conditions and prevent said cable sagging to a point where it may engage the wheels of a vehicle below their vertical center.

With these and other objects in View, the invention consists in certain novel details of construction and combinations and arrangements of parts, all as will be hereinafter more fully described and the novel features thereof particularly pointed out in the appended claims. 7 1

In the accompanying drawings,

Figure 1 is a top plan view of a guard embodying the present improvements;

V Fig. :2 is an elevational view of the guard in the position it assumes when lowered across a road;

Fig. 3 is a detailed View, partly in section, illustrating the attachment of one of the cable ends to its support, so as to permit flexing of said cable;

Fig. is a side elevation of the snubbing device for the guard;

- Fig. 5 is a transverse view of said snubber;

ter indicated at 12- The mechanism for rais- 100 mg and lowering the guard forms no part of the present invention, so that the same need not be described in detail herein. The same i is true of the mounting of the guard, it only being necessary that it be capable of swinging in a horizontal plane as well as in a vertical plane, a

Carried by said support is the barrier proper of the guard, said barrier being in the form of a cable 1 3,whose ends are attached to the pivoted end of support 10 andwhose intermediate portion is placed around the annular member 14 at the free end of said suport. tb increase the strains which it may withstand when impacted against byan approachingvehicle. For this reason, support 10 is fbowed or offset intermediate its free end and its pivoted end, said cable'spanning this effect portionand the space between the two parts eing at least as great as the extent to which This flexing of the said cable, may flex. cable when impacted against by an approachingvehicle, is obtainedby having one or both of its ends yieldingly or'movably attached to support 10. In the present instance, each end of said cable 13 isfirmly secured to a block 15 slidably mounted in a cylinder 16 on the pivoted endof said support 10. At-

tached to said block15 is a tubular member I plow steel cable has been used for the barrier,

andjits ends have been attached, as described, to permit a movement of 18 inches thereof,

' this giving a 5 -foot flexing of the cable when v engaged by an approaching vehicle. With this arrangement, the cable is capable of withstanding approximately 27,000 pounds, or 13 tons, whereas, ifit could not flex, it could not stand as high as'1500pounds. After the tubular member 17 carried by bloclr15 at the'ends of the cable has gone solid against the end of cylinder 16, the cable can not flex any further, and the strains are then transmitted to the snubbing device hereinafter described. i v

This snubbing device may assume various constructions, but in the present instance it is illustrated as consisting of a snubbing post 19, movable along guides 20, said snubbing post having attached thereto a cable 21 which passes over a sheave 22 and has its opposite end fixedly attached in a desirable way to a portion of the base on which the snubbing mechanism is mounted; Sheave 22 is journaled on the rod or stem 23' of a piston or plunger 24 slidable in an' oil cylinder 25 5 against the pressure'of oil in'said cylinder This barrier is adapted to'flex in. order olearancearound said plunger head and a comparatively small duct 38 extending through said head, the oil between the head 24 and one end of cylinder 25 escapes, so as to permit a movement of sheave 22, whereupon snubbing post 19 and the support 10-are likewise permitted to move. After whatever force that has been exerted on the guard to swing said parts is relieved or, removed, spring 26 tends to force sheave 22 away from cylinder 25, and underthese conditions the oil that has previously escaped around the other head 24 is free to flow through a comparatively large duct 29 in said head. This duct 29 is closedat one end by a flap valve 30, said valve being adapted to close duct 29 when sheave 22is moved toward the cylinder 25.

. 'When installed, the'guard is arranged so that avehicle approaching the railroad crossing will engage the barrier 13 and if itimpacts against the same, said cable will first be flexed and after its limit of flexing has be-enreached, the entire guard, togetherwith snubbing post 19, will 'inovetoward the railroad crossing, as just described. However, if avehicle should possibly gain entrance of the gates at opposite sides of the crossing while thegates were in elevated position and not clear'said crossing before the gates have been lowered (due to an approaching train),

support 10 must, of cours'e, be capableof moving in the direction opposite to that previ ouslydescribed, so that the vehicle can clear the tracks; This is. accomplished byhaving the snubbing post 19 formed at one'side with a vertically disposed web 31, whose'upper end surface is inclined so as to guide the annular member14 upwardly until it ,will clear the upper extremity of'said snubbing post, as indicated in dotted'lines in'Fig- 4. After member 14 has cleared snubbing post 19, the vehicle can then push the guard aside and clear the tracks. 'U pon return of the guard, afterthe vehicle has passed through, the annular member 14 engages a web 32 adj acent the snubbing p'o'st'19 and elevates the same so that'it willpass over said snubbing post-until the opening therein registers'with the snubbing post,-whereupon it will drop into its'normal position around said snubbing post, i. v

A flexible barrier of this type, carried by a supporting member, the barrier being adapted to flex a predetermined extent,

whereupon it, together Withits support, is

adapted to move in a horizontal plane against the forces exerted by the elements of the snubbing device, provides a guard against which a vehicle traveling at a fairly high rate of speed can impact without danger of damaging the vehicle to any appreciable extent. It will be understood that the initial flexing of the cable itself has no effect on deceleration of the moving vehicle, the cable merely serving the purpose of transmitting the forces exerted thereon to the snubbing device.

The flexing of the cable is only important in that it can, under such conditions, withstand greater strains. For the above reasons, the tension of springs 18 in cylinders 16 need only be such as to be capable of returning the cable (after flexing) and maintaining it in a position or vertical plane a short distance above the vertical center of various vehicle wheels. In view of the comparative lightness of these springs 18, therefore, the flexing of the cable in actual operation is substantially instantaneous with the impact of the vehicle. From the foregoing, it will be clearly seen that the support 10 is not engaged by the ve hicle and is used primarily for the purpose of raising and lowering the cable.

In the drawings, the guides 20 of the snubbing mechanism are shown as extending parallel to the center line of the roadway. Under these conditions, the support 10 must flex somewhat as it swings horizontally, but the extent of this flexing may be reduced by arranging guides 20 at an angle to the center line of the road. For instance, the guide 20 which is between post 19 and the pivotal center of support 10 is essentially a thrust member in that it prevents movement of post 19 laterally toward the road. Therefore, altering the position of the guides 20 so that they are inclined toward the road, flexing of the support will naturally be reduced. Furthermore, the post 19 naturally has a tendency to bind on the guide 20 that resists the lateral movement referred to, so that this binding action may, likewise, be reduced by inclining the guides toward the roadway.

What I claim is:

1. A railroad crossing guard comprising a support pivoted for horizontal movement, a barrier supported on and positioned to one side of said pivoted support, and means for resisting swinging movement of said support, said flexible barrier being yieldingly supported on said support to permit flexing thereof, the extent of flexing being less than the distance between said barrier and support.

2. A railroad crossing guard comprising a pivoted support having an offset portion and adapted to be positioned across a road, means for yieldingly maintaining said support across a road, and a flexible barrier carried by said support and spanning the oflset portion thereof.

3. A railroad crossing guard comprising a substantially rigid support pivotally mounted adjacent one end to swing in a horizontal plane, means connected tothe opposite end of said support for holding the same against swinging movement until a predetermined pressureis imposed thereon, and a flexible barrier positioned to one side of the pivoted barrier, and means for limiting flexing of said barrier before a vehicle engages saidsupport.

4. A railroad crossing guard comprising a rigid support pivoted to swing in a horizontal plane, said support having a horizontally offset portion adapted to extend transversely across a road, a flexible cable attached to said support and spanning said offset portion thereof, and means for limiting flexing of said cable to a distance less than that between the normal position of the cable and said support.

5. A railroad crossing guard comprising a pivotally mounted support adapted to be positioned across a road, and a flexible barrier carried by said support and spaced to one side thereof, one end of said barrier being yieldingly attached to said support to permit flexing thereof and said barrier being movable with the support when the latter moves on its pivotal center.

6. A railroad crossing guard comprising a support adapted to be positioned across a road, said support being pivoted to swing in a horizontal plane, a barrier carried by said support and spaced to one side thereof, one end of said barrier being yieldingly attached to said support, and means for yieldingly maintaining said barrier and support in position across said road.

7. A railroad crossing guard comprising a support adapted to be positioned across a road and pivoted at one end to swing in a horizontal plane, a flexible barrier having its ends attached to said support and spaced from said support throughout the major portion of the length thereof, one end of said barrier being yieldingly attached to said support, and means for yieldingly maintaining said support and barrier in position across a road.

8. A railroad crossing guard comprising a support adapted to be positioned across a road and pivoted at one end to swing in a horizontal plane and upwardly from said plane, a snubbing device adapted to be en gaged by the other end of said support, and a flexible barrier carried by but spaced from the major portion of said support and said barrier being movable with the support when the latter moves on its pivotal center.

9. A railroad crossing guard comprising a support pivoted at one end to swing in a horizontal plane and upwardly from said plane and adapted to extend across a roadway, said support having an offset intermediate portion, and a cable spanning said ofi'set portion fixedly attached atone end to said support andyieldingly attached at its other end to said support and said barrier I being movable with the support when the latter moves on its pivotal center.

CLARENCE M. DAVISON.

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